Unit3AngleMeasurement（1）HeNanGeologyMinaralCollegeYangLikun01BasicTermsCONTENTS目錄03VerticalAngle02HorizontalAngle04InstrumentforanglesmeasurementPARTONEBasicTerms01BasicTerms1.verticalline

：Averticallineatanypointontheearth’ssurfaceisthelinethatfollowsthedirectionofgravityatthatpoint.Itisthedirectionthatastringwillassumeifaweightisattachedatthatpointandthestringissuspendedfreelyatthepoint.Atagivenpointthereisonlyoneverticalline.地球表面任一點(diǎn)的垂線是指這點(diǎn)上沿著重力的方向的線。如果在這點(diǎn)上用線懸掛一個(gè)重物，當(dāng)線自由靜止時(shí)，這條線所呈現(xiàn)的方向即重力方向。在給定的一個(gè)點(diǎn)上只有一條垂線。suspendedadj.暫停的、懸浮的assumev.呈現(xiàn)2.horizontalline：Ahorizontallineatapointisanylinethatisperpendiculartotheverticallineatthepoint.Atanypointthereareanunlimitednumberofhorizontallines.一點(diǎn)上的水平線是垂直于過該點(diǎn)的垂線的直線。過任一點(diǎn)的水平線有無(wú)數(shù)條。beperpendicularto垂直于……BasicTerms3.horizontalplane：Ahorizontalplaneistheplanethatisperpendiculartotheverticallineatthepoint.Thereisonlyonehorizontalplanethroughagivenpoint.過一點(diǎn)的水平面是垂直于過該點(diǎn)的垂線的平面。過給定的一個(gè)點(diǎn)只有一個(gè)水平面。BasicTerms4.verticalplane:Averticalplaneatapointisanyplanethatcontainstheverticallineatthepoint.Thereareanunlimitednumberofverticalplanesatagivenpoint.過一點(diǎn)的豎直面是包含過該點(diǎn)的垂線的任一平面。過給定的一點(diǎn)有無(wú)數(shù)個(gè)豎直面。BasicTermsPARTTWOHorizontalAngle02HorizontalAngleAhorizontalangleistheangleformedinahorizontalplanebytwointersectingverticalplanes,orahorizontalanglebetweentwolinesistheanglebetweentheprojectionsofthelinesontoahorizontalplane.水平角是指在一個(gè)水平面內(nèi)由兩相交的豎直面形成的角，或者說，兩條線之間的水平角是這兩條線在水平面上的投影線的夾角。intersectv.相交，交叉PABabpbhorizontalplaneFigure1Forexample,observationstodifferentelevationpointsBandCfromAwillgivethehorizontalangle∠bacwhichistheanglebetweentheprojectionsoftwolines(ABandAC)ontothehorizontalplane.例如，在A點(diǎn)觀測(cè)不同高度的B和C點(diǎn)，其水平角∠bac是由AB和AC兩條線在水平面上的投影構(gòu)成的。HorizontalAngleItfollowsthat,althoughthepointsobservedareatdifferentelevations,itisalwaysthehorizontalangleandnotthespaceanglethatismeasured(Figure1).由此得出結(jié)論，雖然被觀測(cè)的點(diǎn)在不同的高度上，測(cè)出的總是水平角而不是空間角。HorizontalAngleThehorizontalangleisusedprimarilytoobtainrelativedirectiontoasurveycontrolpoint,ortopographicdetailpoints,ortopointstobe

setout.水平角主要用來由聯(lián)測(cè)控制點(diǎn)獲得相對(duì)方向，或者地形測(cè)量碎部點(diǎn)、或者放樣點(diǎn)。HorizontalAnglePARTTHREEVerticalAngle03Averticalangleisananglemeasuredinaverticalplanewhichisreferencedtoahorizontallinebyplus(up)orminus(down)angles,ortoaverticallinefromthezenithdirection.豎直角是在一個(gè)豎直面內(nèi)參考于水平線的正（仰）角或負(fù)（俯）角，或者相對(duì)于一個(gè)天頂方向的垂線的角。VerticalAnglePlusandminusverticalanglesaresometimesreferredtoaselevationordepressionangles,respectively.正負(fù)豎直角有時(shí)分別被稱為仰角或俯角。VerticalAngleAverticalanglethusliesbetween0°and±90°.豎直角位于0～90度之間。liev.位于VerticalAngleZenithisthetermdescribingpointsonacelestialspherethatisasphereofinfinitelylargeradiuswithitscenteratthecenteroftheearth.天頂方向是一個(gè)術(shù)語(yǔ)，用來描述在天球上的點(diǎn)，天球是一個(gè)半徑無(wú)限大的球，其中心在地球中心。celestialsphere/s??lesti?l//s??lest?(?)l/adj.天空的，天上的天球infinitely無(wú)限地VerticalAngleThezenithisananglemeasuredinaverticalplanedownwardfromanupwarddirectedverticallinethroughtheinstrument.天頂距是一個(gè)在豎直面內(nèi)從一個(gè)過儀器的被定向?yàn)橄蛏系呢Q直方向線向下測(cè)量的角。VerticalAngleItisthusbetween0°and180°.它的范圍是從0到180度。Obviouslythezenithangleisequalto90°minustheverticalangles.顯然，天頂距等于90度減去豎直角。VerticalAngleVerticalanglesorzenithsareusedinthecorrectionofslopedistancetothehorizontalorinheightdetermined.豎直角或天頂距用于斜距化平距的改正或者高程的測(cè)量。

VerticalAnglePARTFOURInstrumentusedanglesmeasurement04InstrumentusedanglesmeasurementForthemostpart,theinstrumentusedinthemeasurementofanglesiscalledatransitortheodolite,althoughanglescanbemeasuredwithclinometers,sextants,orcompasses.在極大程度上，用來測(cè)角的工具被稱為經(jīng)緯儀，雖然角度可以用傾斜儀、六分儀、或羅盤儀來測(cè).Thetheodolitecontainsahorizontalandverticalcirclesofeitherglassorsilver.經(jīng)緯儀有一個(gè)玻璃的或鍍銀的水平度盤和豎直度盤。InstrumentusedanglesmeasurementThehorizontalandverticalcirclesoftheodolitecanbelinkedtocircularprotractors

graduatedfrom0°to360°inaclockwisemannersetinhorizontalandverticalplane.經(jīng)緯儀的水平度盤和豎直度盤與順時(shí)針刻了0到360度刻劃的圓量角器相連。InstrumentusedanglesmeasurementInstrumentusedanglesmeasurementThehorizontalcircleisusedwhenmeasuringorlayingoffhorizontalanglesandtheverticalcircleisusedtomeasureorlayoffverticalanglesorzenithangles.測(cè)或放樣水平角時(shí)用水平度盤，測(cè)或放樣豎直角或天頂距時(shí)用豎直度盤。layoff撥、放樣Instrumentus